You cant tell the fld_race and fld_raceimg without looking at the normal euro mir mobs that are within the database already.
There isnt a known list for all the race & raceimg's.
To find the imgindex for a mob is quite simple really, bit of maths for you but very simple :P
You find the mon you want (mon16 for example) you minus 1 from the 16 equals 15, right? keeping up with me uh?
then you find the mob witin the wil file counting through them, say its the 5th mob in that wil file you want. you also need to minus 1 off that which is 4.
so now you have 15 & 4, you combine them together to make 154.
The number of the mon file is also first, obviously followed by the monster count within the wil file.
Hope this helps. It would be so much easier to show you than explain but maybe you can understand. Im not very good at explaining things if you didnt guess :P